PEEP/DECIDE/GRAPH is an interactive programming system written in SAIL, the Stanford Artificial Intelligence Language, and operating on the DCRT PDP-10 computer. PEEP is designed for picture processing applications, DECIDE is intended for algorithmic decision making and exploratory data analysis, and GRAPH has capabilities for two and three dimensional graphics. The system was originally written for the NCI Bladder Cancer Image Processing Project but is of wide utility. We will continue to make PEEP/DECIDE/GRAPH available for public use.